Power slip



Dec.'30, 1952 J. MOON 2,623,257

POWER SLIP Filed March 11, 1946 2 SHEETS-SHEET 1 256 Zip 42726 JNVENTOR. JA MES MOON X Immm- A TTORNE Y J. MOON POWER SLIP Dec 30 1952 2 SHEETS-SHEET 2 Filed March 11, 1946 INVENTOR. JAMES MOON A T TORNE Y II: a?? 1 5 Patented Dec. 30, 1952 UNITED STATES PATENT OFFICE POWER SLIP James Moon, Altadena, Calif.

Applicaticn March 11, 1946, Ser al No. 653,515

3 Claims.

This invention relates to oil welldrilling equipment, and particularly pertains to power slips.

During oil well drilling operations concerned with the installation or removal of well tubingit is common knowledge that considerable time is expended in placing and removing pipe slips for temporarily gripping pipe, tubing, or casing as required when pipe joints are set up or broken. The pipe slips ordinarily used are heavy and cumbersome, and are placed and removed by manual operation. This in itself consumes considerable time and effort. It is desirable, therefore, to provide means for lowering and raising the slips from their set position, and which means will not require manual operation but can. be produced by the application of force. It has also been found that when the pipe joints are broken there may be sufficient liquid within the portion of the pipe above the broken joint to flow out from the joint and cover the slips and associated equipment, thus making the operation of removing and setting the slips a disagreeable one, and also making it difficult to handle the slip parts. Heretofore, power slips have been pro vided which include the use of a solid or segmental supporting ring from which slip's ar suspended. These made it necessary to apply power to the ring and to attempt to lift all of the slips with equal force. times the slips on one side of a lifting ring will bind, thus tending to cause the entire slip structure to jam, and it is further obvious that due to the overhead" construction of the lifting means these parts may become covered with oil and other liquids from the well. It is desirable, therefore, to house the slips and other moving parts so that they will be consolidated in a relatively small space and will be effectually protected from extraneous materials present while tubing is being set or withdrawn.

It is the principal object of the present invention to provide a slip unitincluding a plurality of slips each equipped with individual power lifting means, the structure enclosed within a housing so designed as to insure that as" the slips are lifted from their set position they will simultaneouslyretract from the side walls of the pipe which has been gripped and will thusgive a maximum clearance for the pipe and its joints during a minimum powerstroke.

The present invention contemplates a base structure containing slip seats, slips and power It is obvious that at The invention is illustrated by way of example in the accompanying drawings in which:

Figure l is a view in side elevation of a slip unit embodying the present invention and indicating the housing by dotted lines and one of the lifting cylinders in section, the structure further indicating the slips in their uppermost positions.

Fig. 2 is a view in side elevation similar to that shown in Fig. l and indicates the slips in their lowermost positions.

Fig. 3 is a view in transverse section through the structure as seen on the line 3-3 of Fig. 1 and shows the slips in their elevated and expanded positions.

Fig. 4 is a view intransverse section as seen on the line 4+4 of Fig. 2 and shows the slips in their set positions.

Fig. 5 is a view in vertical section through one of the slip unitsas seen on the line 5 -5 of Fig. 4.

Fig. 6 is a view in plan as seen on the lin 6-6 of Fig. 2 and shows the completely assembled structure with the outer housing indicated by dotted lines.

Fig. '7 is a view in side elevation showing the complete slip structure as viewed at right angles to Fi 2.

Fig. 8 is a view indicating the applicationof the present' in-vention to the floor of an oil well derrick and shows a length of pipe extending therethrough.

Referring more particularly to the' drawings, Ill indicates the floor of an oil well derrick through which a well pipe or tubing ll extends into the bore I 2 of a well. Exposed above the iioor m of the derrick is suitable supporting means fora slip structure. With the use of the present invention separate slip seats for drill slips are not necessary since the entire slip struc ture is included within the power slip unit It which is mounted upon a suitable support, as indicated in Fig. 8, and through which the string of pipe ll extends.

With reference to Fig. 6 it will be seen that the slip unit comprises two substantially semicircu- Iar sections I5 and [6. These include complementary semicircular slip seats" l7 and [8. The slip seats, as shown in" Figs. 1 and 3, aresubst'am tially semicircular in section and have longitudinally concaved inner faces 19 and 20. These inner faces converge toward the bottom of the slip unit and terminate in a central opening 2|. The lower portions of the members I! and is are formed with semicircular base plates 22 and 2.3 at their bott'o'msto rest upon the rotary table. The upper ends of the slip seats i l and I13 are curved inwardly to form horizontal top faces 24 and 25 which carry upwardly and outwardly flaring sections 25 and 27, respectively, and downwardly extending lips 28 and 25. The upwardly and outwardly flaring portions 25 and 21, as shown in Fig. 6 of the drawing, provide a central circular passageway through which a pipe or tubing Il may pass. This tubing will of course pass through the bottom opening 21. In order that the slip seat sections I! and I8 may be fitted conveniently around a pipe or tubing suspended in a well the section I? is formed with a pair of lugs 32 and 33 which are spaced from each other to receive an intermediate lug 34 formed integral with the slip seat section I5. Aligned openings extend through the three lugs to receive a lock pin 35. It is to be understood that the lugs and a lock pin occur upon diametrically opposite sides of the slip structure with the lugs overlapping ach other to receive the pin 35 and to hold the slip seat structure in a rigid condition during operation. The longitudinal centers of the pins 35 lie in the central parting plane between the two slip sections. This is shown in Fig. 6. Attention is directed to the fact that the contiguous parting edges of the slip seat units I1 and [8 are different at opposit sides of the center of. the unit. This difference is represented by angular faces 36 and 31 which make it possible for the lock pin 55 upon the opposite side of the unit to be removed while hinging the slip sections I7 and I8 around the key 35 which is contiguous to the inclined clearance faces 36 and 31.

Associated with the slip seat sections are slip units 38 and 39. These units each comprise a pair of slips 45 and M. The arcuate length of each of said slips is slightly less than one-quarter of the circumference of the circle within which all four of the slips lie when the clips are set around the pipe II. The arcuate lengths of the slips are such as to cause a space 39 to occur between the free edges of the slips. The slips are disposed with relation to the slip'seats Ill and. I8 so that key members 40 set into the parting faces of the seat units I1 and I8 and project into the spaces 39' to prevent movement of the slips circumferentially. The key members M are mounted on each of the parting faces of the members I1 and I8. When the faces are in locked position, these key members on the contiguous faces of IT and I8 meet to form a key which extends partway up the faces, as indicated on Figs. 2 and 4. They project into the conical space so that each of the hinged parts forms a somewhat less than a semi-circular half of the slip, each seating between the diametrically opposed keys when the slips are in pipe gripping position (see Figs. 2 and 4). The contiguous edges of slips 4!) and 4| in each pair are hinged together near the upper and lower edges by lugs 32 carried upon the slip 40 and intermediate lugs 43' carried upon the slips 4|. Hinge bolts 54 pass through openings in the registering lugs so that the slips 40 and 4| may pivot around the vertical axes established by the bolts 44. Extending upwardly from the contiguous edges of slips 40 and 4| are lugs 45 and 45, respectively. The lugs 45 and 45 project upwardly and are so spaced laterally of the slips as to cause the slips to hang with their gripping edges vertical when the slips are suspended from said lugs; The lugs 45 and 46 are provided with loops 51 and, 48, respectively. These loops, as shown. by dotted lines in Fig. 7 of, the drawing, are se- 4 cured by a fastening rivet 49 passing through an opening 50 in the lug. The loops form eyes which are of relatively large diameter and receive shackles 5| and 52, respectively, which are secured by pins 53 and 54 to the free end of a lifting arm 55. The shackles and loops have openings of sufficiently large diameter to permit free hinge action of the slip sections with relation to their vertical hinge pins. It is to be understood that while the; articulate connections between the slips and the lifting arm 55 are described with reference to the slip unit 38 that the said structure is used to connect the parts of slip unit 39 with lifting arm 55, which is disposed diametrically opposite to the lifting arm 55. By reference to Fig. 6 of the drawing it will be seen that the lifting arm 55 travels along a vertical slot 51 in the member ii and that the lifting arm 56 travels along a slot 58 in the mem her [8. The ends of the lifting arms are formed with a transverse end portion through which the pins 52 and 53 pass. In order to accommodate this portion the upper end of the slots 51 and 58 are T-shaped, as indicated at 59. The lifting arms 55 and 56 extend upwardly and outwardly and each terminates in a crosshead 6B. These crossheads are fixed at the upper ends of plunger rods 6|. As shown in Fig. 1 of the drawing the lower ends of each of these rods are fitted with a piston 52 which reciprocates within a cylinder 63. A pair of these cylinders is provided, one carried by the unit H, and the other carried by the unit I8 and disposed diametrically opposite each other along a median plane which intersects the opening 30. The lower ends of each of the cylinders is fitted with a head 54 formed with a fluid supply duct 55 therein. These ducts communicate with conduits 66 through which a supply of fluid is delivered under pressure. This fluid is obtained from any desired source and will act upon the pistons 62 to move the plunger rods 6| upwardly. The upper ends of the cylinders are fitted with cylinder heads 61 carrying packing glands through which the plungers 6| may reciprocate. The cylinder heads 61 are held securely with relation to the member 54 by stay-bolts 58. The upper ends of the cylinder heads 61 are tubular and are seated within brackets 69 which are formed integral with the units l7 and I8 and which cooperate with members If! in holding the cylinders stable. Cap screws II are provided to fasten the members II! with relation to the brackets 69.

Extending outwardly from diametrically opposite sides of the crossheads 60- 'are wings I2. Attached to these wings are helical springs 13.

The lower ends of the springs are attached to brackets 14 held on the base portions 22 and '23. It will thus be evident that when pressure fluid is introduced into the cylinders 63 they will force the pistons 62 upwardly against the tension of the springs I3, and that when the delivery of pressure fluid is interrupted the pistons 62 will be retracted to their lowermost positions by the action of the springs I3.

Attention is directed to the fact that the longitudinal axes of the cylinders 53 and the plungers 5| are not parallel to the faces I9 and 20 of the slip seat units but are at a lesservertical angle than the faces I9 and 20. This insures that as the slip units 38 and 39 lift, their wickered' faces 15 will not only draw away from the surface of the pipe II buttheir arcuate back faces will tend to draw away from the faces l9 and 20 of the seats. r Y

' Thus it will be. observed that the faces I9 and 20, which. act as guideways for the. slips as they move into and out of pipe gripping position, are inclined to the vertical at an acute angle. The complementary back faces of the slip elements move over these guideways. The common suspension point of the arms 55 and 55 each travels along a line. parallel to the axis of the: cylinder 53 which is inclined at an: acute angle to the vertical less than the inclination of the faces I9 and 2B.

Byreference to the drawing it will. be observed that the lug 45 on slip 40 is spaced from lug 46 on. slip 40, one on each side of the hinge 44, and each lug is positioned. off center outwardly from the pivotal axis of the bolt 44. The loops 4'! connected to lug 45 and the loop 48 connected to lug 46 are. both connected by means of the pins. 53 and 54 to the free end of the lifting arm which is disposed intermediate the lu s 45 and 46. Itv will also be observed that the contiguous faces 36 and 31' are angled backward to give an angular opening between the. faces so that they are relieved to permit the hinged slip to open on the hinge.

As is evident from Figs. 1, 3, 4, and 5, the points of suspension formed by the lugs 45' and 55 and the common suspension point .on the. arms 55 and 5B are on. a plane which. is displaced off center outwardly from a parallel plane passing through the hinge of the slips. When the common suspension point for the loops 4'! and 58 is elevated to lift the slip elements 40 and ll upwardly from the inclined face of the bowl, the direction of travel of the suspending means draws the slips away from the guideway and also away from the pipe positioned in the slips. The weight of the slips exerts a tension force on the loops which opens the slip elements onthe hinge.

Due to the inclination of the faces I9 and 29 and the line of travel of the suspending means 55, the slips are moved outwardly to bring. them away from the faces I9 and 20 as they arefreely suspended on their common suspension point via arms 55 and 55. Likewise when the slips are lowered so that the slips engage the inclined guideways formed by the inclined curved inner faces I5 and 20, the continued lowering of the hinged slips along the guideways will simultaneously close the slips on their common hinge.

It is to'be understood that the slip sections 49 and M are loosely connected to the arms. 55 and 56 by the linkage which includes the loops. 4! and 48 and the shackles 5| and 52. It will also be noted by reference to Figs. 3 and 4 thatthe point of connection. of the linkage with the slip sections Ml and 4| is off-center from the pivotal. axis of the bolts 44. The direction of the off-center connection with the shackles is outwardly of the slips so that when the slip units 38 and 39 are lifted there will be a tendency for the slip sections 40 and II to swing outwardly and away from the pipe II, as shown in Fig. 3 of the drawing.

In operation of the present invention the slip structure is constructed as shown in the drawings and may thereafter be mounted upon a derrick floor I3 with the operating structure enclosed within a housing I6. When the structure has been thus mounted it is to be understood that the two sections I1 and I8 will be temporarily held together by the pins 35. This W111 cause the structure to embrace a pipe which extends downwardly through the central opening 30. Atthis: same time it is to be understood that the pistons' 62 are in their retracted positions with the slip units 38 and 39 disposed adjacent to the bottom of the slip faces I9 and 20. The slips are held in this position by the tension of the springs I3. When it is desired to introduce a string of pipe into the slip structure l4 fluid under pressure is delivered through the pipe 55. This will force the piston 62 upwardly and will move the piston rods BI upwardly while lifting the arms 55 and 56. Attached to these arms are the articulate slip units 38 and 39 disposed in their uppermost positions. These units will assume the position indicated in Fig. 3 cf the drawing. Here it will be seen that the separate slips 49 and 41 have swung outwardly, in the direction of the arrow 11, with relation to their vertical pivotal axes as established by the bolts M. At the same time the articulate slip units 38 and 39 will have moved laterally of the vertical axis of the pipe II so that a clearance opening is provided through which a pipe II may be passed. After the pipe is in a desired position the pressure fluid delivered through pipe 55 may be relieved from the cylinders 63. This will allow the slips to be moved downwardly into wedging engagement between the slip faces l5 and 29 and opposite sides ofthe pipe I I. This downward movement is accomplished by gravity and by the action of springs '53. When the wickered faces I5 of the slips ti! and ii engage the surface of the pipe ii there will be a tendency for the weight of the pipe to force the slips downwardly to a wedging position against their seats. This freedom of action will be afforded due to the loose connection between the articulate slip units 39 and 13 and the arms 55 and 56. Thus, the string of pipe will be temporarily supported by the slips. It will be seen by reference to Fig. 4 of the drawing that the keys 49' will be positioned in the spaces 39 between free edges of the slips so that they will be held against rotation around the vertical axis of the tubing. When it is desired to release the slips from their gripping position between the pipe II and the inclined faces I9 and 20 fluid under pressure is delivered through pipes 65 to the cylinders 63. This will act to lift the articulate slip units 38 and 35 from theirwickered position and will at the same time tend to draw them away from the inclined faces I9 and 25 and from the cylindrical surface of the pipe II.

It. is to be understood that while the arms 55 and 55 are here described as being lifted by the action of fluid under pressure thatother means of effecting lifting action may be produced, such as by electric solenoids or mechanical structures.

While the invention has been described for use in handling well tubing it is to beunderstood that the structure may be easily adapted for use in handling drill pipe and well casing.

It will thus be seen that the slip structure here disclosed is compact in construction and design, is not liable to get out of order, and will insure that the slips will be raised and lowered from their gripping positions rapidly so that the operation of running tubing in and out of a well bore can be accomplished in a minimum amount of time and with a minimum amount of labor.

While I have shown the preferred form of my invention as now known to me, it will be understood that various changes may be made in combination, construction and arrangement of parts by those skilled in the art, without departing from the spirit of the invention as claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A power slip structure comprising a slip bowl formed in two complementary semicircular sections, means for holding said sections in their assembled relation, said bowl being formed with a central inverted frusto-coni-cal passageway therethrough and through which a pipe may be extended, the upper end of said passageway having a partial. cover thereover and providing a central pipe opening, a pair of slip units, one disposed within each of said bowl sections and within said central passageway, each of said slip units including a pair of arcuate slip segments, the outer sur faces of said segments substantially conforming to the tapered wall surfaces of the frusto-conical passageway when the slips are seated, the inner arcuate faces of said segments being wickered to engage and embrace a pipe extending through said bowl, hinge means between contiguous vertical faces of said slip segments adjacent to the inner arcu-ate faces thereof, whereby a vertical axis is provided with the segments comprising each of said slip units, movable lift rods disposed at a vertical angle less than the inclination of said tapered wall surface, one mounted on each of the bowl sections, an overhanging arm carried by each of said lift rods and extending to points within the frusto-conical passageway, slotted openings in the walls of the bowl being provided to accommodate the same, means for applying power to said rods to move the same axially in their lifting operation, articulate connections carried by each of said arms and attached separately to the slip segments of a slip unit to be lifted thereby, the point of attachment of the articulate connections with the slip segments being adjacent their contiguous edges and off-center from the axes of their ver tical hinges, whereby when the slip units are lifted from their wedging position between the inclined faces of the slip bowl and the cylindrical face of a pipe the slip segments of each unit will swing outwardly to a position of clearance with relation to the pipe.

2. A power pipe slip structure comprising a slip bowl formed in two semicircular sections, means for temporarily holding the sections together, a base formed at the bottom of the structure when the bowl sections are assembled, a frusto-conical bowl wall projecting upwardly and outwardly from the base, the lower end of said wall termimating in an opening through which a pipe may pass, the upper end of said wall terminating in a cover portion having a central opening through which a pipe may pass, guide flanges at the opposite sides of said upper opening to guide a pipe therethrough, vertical slots formed through the side walls of the upper portion of each of said bowl segments-fluid pressure cylinders, one mounted upon the base portion of each of said bowl segments and being disposed diametrically opposite to each other when the bowl is assembled, the longitudinal axes of said cylinders being at a lesser degree to the vertical than the inner surface of the'frusto-conical bowl wall, pistons, one within each of said cylinders, a lifting rod connected to each of said pistons and extending upwardly along opposite sides of the bowl, a pair of inturned arms, one secured at the upper end of each lifting rod and extending through a complementary vertical slot in the side wall of the bowl, a pair of slip units, one associated with each of said arms, each of the slip units comprising a pair of arcuate slip segments, the contiguous edges of which are spaced from each other, a hinge structure disposed between the contiguous edges of said segments and adjacent to the inner faces thereof, upwardly extending lugs carried upon each of the slip sections and contiguous to the edges thereof, articulate linkage connecting the free ends of the lifting arms and said lugs, the lugs and linkage being off-center from the vertical axes of the hinges, means for delivering fluid under pressure to the cylinders to lift the pistons, and spring means yieldably resisting said movement.

3. The structure of claim 2 including an outer shell substantially enclosing the aforementioned structure and providing a housing therefor.

JAMES MOON.

REFERENCES CITED The following references are of record in the file of this patenti UNITED STATES PATENTS Number Name Date 1,341,702 Black June 1, 1920 1,469,894 Clarke Oct. 9, 1923 1,548,559 Simpson Aug. 4, 1925 1,534,227 Livergood Apr. 21, 1925 1,656,864 Martin Jan. 17, 1928 1,693,478 Davis Nov. 27, 1928 1,725,666 Morrow Aug. 20, 1929 1,872,105 Black Aug. 16, 1932 1,945,876 Young Feb. 6, 1934 1,966,906 Standlee July 17, 1934 2,034,101 Howard Mar. 17, 1936 2,063,378 Hiniker Dec. 8, 1936 2,126,933 Stone et al Aug. 16, 1938 2,131,400 Johnson Sept. 27, 1938 2,231,923 Koen Feb. 18, 1941 2,269,888 Sharp Jan. 13, 1942: 2,340,597 Kelley Feb. 1, 1944- 2,491,711 Calhoun Dec. 20, 1949' FOREIGN PATENTS Number Country Date 462,257 Great Britain Mar. 5, 1937 

